
With obesity affecting over 42.4 percent of the American population (Hales et al., 2020), artificial sugar sweeteners have been advertised by companies and physicians for years as an alternative to giving up one’s sugary diet (and its resulting health risks) without sacrificing taste. However, new research suggests a specific artificial sweetener, sucralose, could potentially have adverse effects on multiple bodily functions, including one of our most important organs, the heart (Corliss et al., 2023). With cardiovascular disease being the leading cause of death among American adults, the effects of sucralose on heart health raises questions concerning the true benefits and safety of these low calorie substitutes. Whether it’s the Splenda in your coffee, “sugar-free” Hershey’s chocolate, or Diet Mountain Dew, sucralose has become a staple in many American diet foods today - but are these types of sugars secretly killing us?
What are artificial sweeteners?
To start, one should understand the mechanics of how these artificial sweeteners work. First, they are not as complex as one may think. The majority of sweeteners use sucrose (traditional table sugar) as a base model. Taking a sucrose molecule, chemists change one or more functional groups attached to the molecule to create a different structure. Why? By changing functional groups, we can manipulate the level of sweetness recognized by our taste receptors. In the case of sucralose, three of the hydroxyl groups present on a sucrose molecule are substituted with chlorine atoms. By slightly altering sucrose’s structure, sucralose becomes over 600 times sweeter than traditional sucrose, meaning only a fraction of the compound is needed to obtain the same level of sweetness as table sugar (Risdon et al., 2021). Given the small amounts needed to sweeten a product, the calorie content when we use sucralose is essentially zero.
Yet to many consumers, the idea of a product tasting almost identical to sugar without leading to any health consequences seems too good to be true, begging the question, can you have your cake and eat it too? Considering sucralose is newer in comparison to table sugar, worries surrounding this substitute’s implications on threats from cancer, heart health, and diabetes, have become a growing concern to users as little is known about the compound’s long-term effects.

Interestingly, two recent studies on sucralose support that consumers should be cautious. The first, the Northern Manhattan Study, conducted in 2012, further assessed the correlation between artificially sweetened beverages, including those with sucralose, and coronary heart disease risk. The study found that daily diet soft drink consumption resulted in a 43% increase in vascular events in comparison to participants engaging in non-frequent diet soda or regular soda consumption (Gardener et al., 2012).
If these results did not worry consumers enough, a prominent online research project led by French scientists in 2009, the NutriNet-Santé study, aimed to test the effects of sucralose on cardiovascular disease and cerebrovascular (brain and its blood vessels) events, including 103,388 participants (Debras et al., 2024). Over three 24-hour periods, volunteers were expected to record in depth their food intake, medical history, and lifestyle habits through an online survey format. These volunteers were tracked for nine years after the survey to assess long term impact. With the average participant consuming 42 milligrams of sucralose daily - comparable to a quarter of a typical diet soda- scientists reported that volunteers who consumed sucralose had a 9 percent higher risk of developing cardiovascular problems, in direct association with increased number of angioplasties (such as unblocking a coronary artery) as a common finding in this population (Debras et al., 2024). Similar to the Northern Manhattan study, sucralose sweetened soda consumption appears to have a significant negative effect in cardiovascular health. Together, these two studies raise legitimate concerns surrounding sucralose usage.
So, is sucralose unsafe to consume? Well, based on the two studies discussed above, it may be. However, there is much more to this story. While these studies strongly support the correlation between sucralose use and heart disease, there are other studies which show the sweetener to have no correlation to heart disease risk. For example, a study conducted in 2018 which aimed to test the correlation between sucralose administration and blood pressure, found no correlation between the two (Pham et al., 2024). Another study conducted in 2022, provided rats with excess amounts of sucralose over an extended period of time to observe its effects on cardiovascular function. These studies found no significant change in body weight, triglyceride or cholesterol levels, nor blood pressure within the sucralose group (Guru et al., 2022). In addition, none of these rats exhibited changes in ventricular wall thickness or heart function, leading scientists to suggest there was no damage caused by sucralose usage. While the NutriNet-Santé and Manhattan Studies point in a negative direction, there are clearly conflicting data sets suggesting sucralose usage to be harmless.
So, who’s right? When comparing the difference in research results, it is important to note the specific study design employed by scientists, and its effect on the data. Looking back at the NutriNet-Santé study, the entire data collection process was conducted online and self-directed. Every dietary record reported was controlled by the patient, instead of a non-biased researcher. This restricts the experimenters' control on outside variables, allowing room for error, as the patient may be biased, not being entirely truthful, or miss details about their diet. In order to achieve more reliable results, one should consider altering study design to include a controlled diet, an in-person assessment (vs. online), and a regimented sucralose ingestion. Furthermore, the Manhattan Study also exhibits flaws within its experimental design (Attia et al., 2021). Dr. Peter Attia, a Canadian-American physician and author, speaks briefly on the study, noting that the diet soda drinking population had other pre-existing health conditions that could have impacted the results of the study, such as higher blood pressure, higher circulating triglycerides, lower HDL cholesterol, and higher pre-existing vascular disease, to name a few - and exhibited a poor diet compared to other participants (Attia et al., 2021). These pre-existing health factors found in the diet soda drinking population may have no correlation to the increase in vascular issues. Yet, it should be mentioned that when the study was then normalized for these variables, comparing similar health profiles of research participants both in the sucralose and non-sucralose populations, researchers noted no significant correlation between vascular events and artificially sweetened soda consumption.
However, while these studies present conflicting views on the effects of sucralose on cardiovascular health, recent data analysis of all the data available suggests sucralose has a link to heart health. A 2024 review suggests a prominent correlation between artificially sweetened beverages and biomarkers associated with cardiovascular disease, including myocardial infarction, acute coronary syndrome, angioplasty, angina pectoris, stroke, and transient ischemic attack (Singh et al., 2024). The review particularly highlights the impact of sweeteners on the high-density lipoprotein (HDL)-to-total cholesterol ratio, as well as their influence on lipid and leptin levels. The review suggests these effects could stem from sucralose’s negative association with diabetes and its ability to impair insulin uptake. By affecting insulin uptake sucralose may indirectly affect cardiovascular health. Beyond its links to diabetes, the World Health Organization (WHO) issued a statement last May discouraging the use of sucralose after it was found to suppress T-cell production in mice, which led to increased cancer rates and inflammation (New Research with Mice Reveals the Dangers of Sucralose et al., 2023). While this may not be directly related to cardiovascular disease, there is evidence suggesting sucralose may impact multiple health concerns and ultimately pose a danger for consumption.
In conclusion, several studies correlating sucralose to heart health suggest that artificial sweeteners may cause harm to our body. Unfortunately, we do not know how harmful sucralose is to our cardiovascular system or its long-term effects, until additional studies are done that incorporate important variables such as preexisting health conditions and study design bias. As a scientist, the results suggest that one should take caution in consumption and use moderation until more is known. Until then, enjoy a crisp Diet Coke on a hot, summer day - but perhaps just one vs. a six pack.
Written by Emily Barson and edited by Aldrin V. Gomes, PhD
References
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Risdon S, Battault S, Romo-Romo A, Roustit M, Briand L, Meyer G, Almeda-Valdes P, Walther G. 2021. Sucralose and Cardiometabolic Health: Current Understanding from Receptors to Clinical Investigations. Advances in Nutrition. 12(4):1500–1513. doi:https://doi.org/10.1093/advances/nmaa185. [accessed 2021 Nov 8]. https://academic.oup.com/advances/article/12/4/1500/6134197?login=true.
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